Gentlemen
i offer my sincerest apologies. the barrel is marked 8,82 as you can see from the photo. i was so excited to post my information i wrote it wrong. i did however learn much about the tolerences and got to see the excelent picture form JS.
Here are some more photos of my luger. you can see the number 4 stamped in the sideplate. also you can see that the inside of the frame is mostly in the white except on the inside of the backstrap where it is just dark. on the underside of the slide there is an "R" on the lug visible in the photo. there are also some numbers on the underside of the toggle, i cant make out the first one but the next two look like a 0 and 3 reading from right to left.
thanks again for all the input. i have learned much.